Problem: Jessica is 48 years old and Daniel is 10 years old. How many years will it take until Jessica is only 3 times as old as Daniel?
Answer: We can use the given information to write down an equation about how many years it will take. Let $y$ be the number of years that it will take. In $y$ years, Jessica will be $48 + y$ years old and Daniel will be $10 + y$ years old. At that time, Jessica will be 3 times as old as Daniel. Writing this information as an equation, we get: $48 + y = 3 (10 + y)$ Simplifying the right side of this equation, we get: $48 + y = 30 + 3 y$ Solving for $y$ , we get: $2 y = 18$ $y = 9$.